Phase equilibria of quasi-binary systems consisting of multicomponent polymers 1 and 2. IV: Poly(ethylene oxide)/poly(propylene oxide) systems

Abstract

To confirm the reliability of the theory of phase equibria of multicomponent polymer 1/multicomponent polymer 2 systems (i.e. quasi-binary systems) and the method of computer experiment based on this theory (Brit. Polym. J., 23(1990)285; 23(1990)299; Polym. Int., 29(1992)219), could point curves (CPC), two-phase volume ratios (R) and critical solution points (CSP) have been determined experimentally for the quasi-binary mixtures of poly(ethylene oxide) (M¯w = 647, M¯w/M¯n = 1.15; M¯w and M¯n, the weight-average and numberaverage molecular weights, respectively) and poly(propylene oxide) (M¯w = 2028, M¯w/M¯n = 1.08; and Mw = 2987, Mw/Mn = 1.13). The hydroxyl end groups of both polymers were methoxylated in advance by the Cooper & Booth method (Polymer, 18(1977)164). The thermodynamic interaction parameter between both polymers, χ12, and the concentration dependence parameters for the above quasi-binary systems were determined by the method proposed in a previous paper (Brit. Polym. J., 23(1990)299). CPC, R and CSP values calculated on the basis of the theory are in good agreement with the values determined experimentally.